Mobile input devices play an important role in enhancing user's experience in using electronic devices. For example, an optical mouse senses a user's hand movement and enables the user to navigate programs in a computer system or other electronic devices. An accurate detection of the users hand movement enables the optical mouse to convey the right information from the user to the computer system.
Another example is a proximity sensing device. A proximity sensing device is commonly used in electronic devices to perform certain functionalities in response to the presence of an external object. An accurate detection of the external object may involve determining a displacement distance between the external object and the sensor. By measuring the displacement distance accurately, the optical sensing device may enable the electronic devices to activate or deactivate certain functionalities. For example, when the proximity sensing device is used in a touch screen enabled mobile phones, the proximity sensing device is used to detect when the mobile phone is moved closer to the user's ear so that the mobile phone may disable its touch screen functionality.
While mobile input devices provide many advantages, some challenges may remain. For example, additional configurations may be desired, so as to provide additional desired functionality.